ln: do not automatically accept zero fee commitment channels

Like anchor channels, these channels require that the user reserves a
UTXO to bump the channel. If we automatically accept this channel type
and the user does not have such reserve available, they are at risk of
losing funds because they cannot fee bump the channel.

Author: carlaKC

lightning/src/ln/channelmanager.rs

@@ -8175,7 +8175,7 @@ This indicates a bug inside LDK. Please report this error at https://github.com/
 		if channel_type.requires_zero_conf() {
 			return Err(MsgHandleErrInternal::send_err_msg_no_close("No zero confirmation channels accepted".to_owned(), common_fields.temporary_channel_id));
 		}
-		if channel_type.requires_anchors_zero_fee_htlc_tx() {
+		if channel_type.requires_anchors_zero_fee_htlc_tx() || channel_type.requires_anchor_zero_fee_commitments() {
 			return Err(MsgHandleErrInternal::send_err_msg_no_close("No channels with anchor outputs accepted".to_owned(), common_fields.temporary_channel_id));
 		}
 
@@ -16123,6 +16123,13 @@ mod tests {
 		assert_eq!(accept_message.channel_reserve_satoshis, 2_000);
 	}
 
+	#[test]
+	fn test_inbound_zero_fee_commitments_acceptance() {
+		let mut zero_fee_cfg = test_default_channel_config();
+		zero_fee_cfg.channel_handshake_config.negotiate_anchor_zero_fee_commitments = true;
+		do_test_manual_inbound_accept_with_override(zero_fee_cfg, None);
+	}
+
 	fn do_test_manual_inbound_accept_with_override(start_cfg: UserConfig,
 		config_overrides: Option<ChannelConfigOverrides>) -> AcceptChannel {